Inequality, cooperation, collective action, and delayed marital unions: papers from the Sixth Joint Japan–US Conference on Mathematical Sociology and Rational Choice

The papers in this special issue were presented at the Sixth Joint Japan–US Conference on Mathematical Sociology and Rational Choice held on August 2016 in Seattle, WA. The conference was cosponsored by two sections of the American Sociological Association (Mathematical Sociology and Rationality and Society) and by the Japanese Association for Mathematical Sociology. Professors Jun Kobayashi (Seikei University), Masayuki Kanai (Senshu University), Kikuko Nagayoshi (Tohoku University), John Skvoretz (University of South Florida), and Douglas Heckathorn (Cornell University) were the conference organizers. The four papers in this special issue are a subset of the papers that were invited for the issue, and these in turn were a subset of all the papers presented. Invited papers were selected by the organizers with an eye toward the generality of problem and depth of mathematical content. All submitted papers were peer reviewed as per the standard review procedures of the journal. Three of the papers are very much in the tradition of rational choice: “Late Marriage and Transition from Arranged Marriages to Love Matches” (Kezuka), “The Survival of Inefficient and Efficient Norms” (Kira), and “Self-organizing Collective Action” (Obayashi). Actors are assumed to gain utility from their actions but how much depends on the actions of others and on parametric factors of theoretical interest. Actors are presumed to maximize utility. Their behavioral strategies include first-order actions (such as cooperate or not) and possible higher-order actions that are sanctioning reactions to lower-order behaviors by others. The aim of analysis, generally, is to derive equilibrium conditions. The problems addressed in the Kira and Obayashi papers are quite broad, namely, collective action and the survival of norms of cooperation. The Kezuka paper is motivated by an empirical puzzle in developed countries with the specific example of Japan, in which there is increasing delay in first marriage. The fourth paper, “What Can You and I Do to Reduce Income Inequality?” (Jasso), differs from the others in several ways. There is no formal model of actors nor functional specification of the factors on which their utility depends. The point of paper is not to assume some action set available to actors and look for equilibrium conditions expressed as stable probabilities over strategies, but rather to develop an understanding of what actions are available to actors if they were to seek to reduce income inequality. In “Late Marriage and Transition from Arranged Marriages to Love Matches,” Kezuka links the delay to a change in the basis of marriage from arranged matches to love matches, a change that is driven in turn by a change in value system from traditional to individualistic. An important background element is the division of the actor population into different social classes because arranged matches can only occur between actors of the same class. Love matches can occur even if the classes of the actors differ. The analysis has two steps: a decision-making step which occurs within periods as single individuals consummate matches (or not) seeking to make an arranged marriage or a love marriage depending on whether they have traditional or individualistic preferences. Between periods, replicator dynamics are applied to the mix of traditional versus individualistic preference holders in the population. The proportions are changed in response to the expected satisfaction achieved by an actor. It is assumed that staying single brings less satisfaction than being in an arranged match, and the latter less than being in a love match. Expected satisfaction depends on the likely success of a search for a mate, which in turn depends on the type of match sought as determined by the searcher’s value system and the associated costs of search but also the current mix THE JOURNAL OF MATHEMATICAL SOCIOLOGY 2018, VOL. 42, NO. 4, 183–185 https://doi.org/10.1080/0022250X.2018.1442403